Polysaccharides comprise an extremely important class of biopolymers
that play critical roles in a wide range of biological processes,
but the synthesis of these compounds is challenging because of
their complex structures. We have developed a chemoenzymatic
method for regioselective deprotection of monosaccharide substrates
using engineered Bacillus megaterium cytochrome P450
(P450_(BM3)) demethylases that provides a highly efficient means
to access valuable intermediates, which can be converted to a
wide range of substituted monosaccharides and polysaccharides.
Demethylases displaying high levels of regioselectivity toward a
number of protected monosaccharides were identified using a
combination of protein and substrate engineering, suggesting that
this approach ultimately could be used in the synthesis of a wide
range of substituted mono- and polysaccharides for studies in
chemistry, biology, and medicine
